Valve for concrete pump



A ril 8, 1969 A. M. SCHAIBQLE ET AL 3,437,311

' VALVE FOR CONCRETE PUMP Filed May 1, 1957 Sheet 5r 3 m r W JN 5 8 \J a Q E d a Q I Q N 8 E V J 0 8 8 U 1NVENTOR$ AARON m. scams/.5 BY JOHN E. LANGDON WILSON, SETTLE a BATCHELDER.

ATT'YS.

A. M. SCHAIBILE ET AL 3,437,311

April 8,1969

VALVE FOR CONCRETE PUMP Filed May 1, 1967 Sheet INVENTORS AARON M. SCHAIBLE I BY I JOHN E. LANGDON WILSON, SETTLE a BATCHELDER.

ATT'YS.

April 96 A. M. same? ETIAL 3,437,311

VALVE FOR CONCRETE PUMP Filed May 1, 1967 Sfieet 3 ors I26 I28 FIG. 5 1

INVENTORS AARON M. SCHAIBLE BY JOHN E. LANGDON 3 WILSON, SETTLE a BATCHELDER.

ATT'YS.

United States Patent 3,437,311 VALVE FOR CONCRETE PUMP Aaron M. Schaible, Rockford, Ill., and John E. Langdon, Racine, Wis., assignors to J. I. Case Company, Racine, Wis., a corporation of Wisconsin Filed May 1, 1967, Ser. No. 635,146 Int. Cl. F16k 1/06, 3/00;F16j 15/50 U.S. Cl. 251-324 4 Claims ABSTRACT OF THE DISCLOSURE BACKGROUND OF THE INVENTION The present invention relates generally to a pump and more particularly to an improved valve for controlling the flow of aggregate-containing material in a concrete pump.

Prior art pumps are available wherein concrete is pumped through two separate passages from a single hopper into a single outlet where the concrete is distributed for final use. In this type of concrete pump, it is conventional to provide a working chamber in each of the passages with a reciprocating piston or pressure member operating within the working chamber to force the concrete along the passage to the outlet. Each passage also includes a pair of valve assemblies respectively located between the supply hopper and the working chamber, and the working chamber and passage outlet.

During operation, one of the valves in each passage is at all times closed while the second valve is open. Thus, while one piston is being actuated to force concrete from the working chamber to the concrete pump outlet, the valve between the working chamber and the outlet is open while the valve in the passage between the hopper and the working chamber is closed. During the work stroke of one of the pressure members, the outlet of the second passage is blocked while the passage between the hopper and the working chamber is open so that concrete can be forced into the working chamber to be subsequently forced through the outlet by the pressure member. Such a concrete pump is generally disclosed in Wilkinson et al., No. 3,198,123 and has found remarkable success in industry.

However, one of the problems with this type of concrete pump is that it is difficult to find a valve which will effectively seal the passageways to prevent separation of concrete fines and liquid from the aggregate in the mixture. -One type of valve which has found partial success in the operation of the above concrete pump is also disclosed in the above mentioned patent and includes a resilient or rubber-gripping nose portion which will effectively seat against the valve seat and envelope any aggregate which may be trapped between the valve plug and the conduit. However, such a valve has found only limited success since it has been found that after short periods of use the resilient portion of the valve plug does not remain sufiiciently rigid to effectively seal the conduit to prevent any flow of liquid or fines. This means the valve plug must be replaced after short periods of use which of course is not only costly but also time consummg.

duit 60.

3,4 3 7,31 l Patented Apr. 8, 1969 SUMMARY OF THE INVENTION In view of the above mentioned shortcomings of the prior art concrete pumps, it is the primary object of the present invention to provide a valve which is not subject to the disadvantages enumerated above which will satisfactorily seal aggregate-containing material efficiently, safely and expeditiously.

Another object of the present invention is to provide an improved valve plug which is self-orienting and has a wiping shoulder that will effectively prevent accumulation of any material within the working chamber to thereby increase the service life of the entire assembly.

A further object is to provide an improved valve plug in which the parts subjected to the greatest wear and deterioration are readily replaceable.

These and other objects and features of this invention will become apparent from the following description and appended claims in conjunction with the accompanying drawings, wherein:

FIGURE 1 is a schematic of a concrete pump incorporating the present invention;

FIGURE 2 is a perspective view of the valve of the present invention;

FIGURE 3 is a vertical sectional view of the valve assembly shown in FIGURE 2;

FIGURE 4 is a vertical sectional view of the valve plug shown in FIGURE 3;

FIGURE 5 is an enlarged fragmentary view of a bearing; and

FIGURE 6 is a valve plug.

Before explaining the present invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and arrangement of parts illustrated in the accompanying drawings since the invention is capable of other embodiments and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein is for the purpose of description and not of limitation.

FIGURE 1 generally discloses a concrete pump 10 which includes a pair of delivery pistons or pressure members 12 and 14 respectively reciprocated in cylinders 16 and 18. The cylinder 16 defines a portion of a working chamber which communicates with a hopper 20 through a conduit 22 having a valve assembly 24 in communication therewith. The working chamber defined in part by the cylinder 16 also is in communication with an outlet 30 through a second conduit 32 having a valve assembly 34 in communication therewith.

Likewise, the second cylinder 18 defines a portion of a second working chamber communicating with the hopper 20 through a conduit 36 with a valve 38 controlling the flow of concrete from the hopper to the cylinder 18. A second outlet conduit 40 has a control valve 42 incorporated therein and communicates with the common outlet 30.

The pistons 12 and 14 are reciprocated within the cylinders 16 and 18, respectively, in such a manner that, as one piston is extended the second piston is simultaneously being retracted. This will provide a substantially con tinued flow of concrete through the common outlet 30. For this purpose, each of the pistons has a rod 50 connected thereto which extends through a partition 52 enclosing one end of respective cylinders 16 and 18. The free end of the rods have a second piston 54 secured thereto each of which reciprocates in a fluid cylinder 56. Suitable fluid pressure may be selectively admitted to the head end of the fluid cylinders 56 through conduits 58 connected to a fluid pressure source (not shown). The head ends of the fluid cylinders 56 are interconnected by a conperspective view of a slightly modified Thus, by appropriate valving (not shown), one of the conduits 58 is placed in communication with a fluid sump while the second conduit is placed in communication with a pressure source. The interconnection between the head ends of the cylinder will cause the trapped fiuid to be exhausted from one of the cylinders into the other cylinder to thereby simultaneously retract one piston while the second piston is being extended.

The respective pairs of valves 24, 34 and 38, 42 are actuated so that when one of the pairs of valves is open the other of the pair of valves is closed. Thus, assuming the valve 24 to be open, as the piston 12 is retracted or moved towards the left in FIGURE 1, concrete will be drawn from the hopper through the conduit 22 into the cylinder or working chamber 16. At the same time, valve 38 will be closed while valve 42 will be open and the piston 14 will be extending to force concrete from the cylinder 18 through the outlet 30.

Each of the valves 24, 34, 38 and 42 is actuated through a hydraulic cylinder 62 having fluid conduits 64, 66 communicating therewith and a piston rod 68 reciprocated therein. The piston rod 68 is connected to a valve plug 70. Suitable hydraulic and electrical circuitry may be provided to simultaneously cause valves 24, 42 to be open while valves 34, 38 are simultaneously closed.

Thus, as piston 12 is being retracted valve 24 will be open while valve 34 will be closed to prevent flow of material from the hopper 20 into the cylinder 16. Simultaneously, piston 14 will be extending or in the discharge stroke and valve 42 will be open while valve 38 will be closed. For a more detailed description of suitable hydraulic and electric circuitry for performing the above functions, reference may be had to the above mentioned patent which is incorporated herein by reference.

As was indicated above, this type of concrete pump has shown remarkable success but has one serious drawback in that valve assemblies heretofore utilized either did not effectively seal the conduit or had such a short service life as to be very costly to maintain. According to the invention, a control valve constructed in accordance with the teachings hereinafter set forth will provide a simple inexpensive readily serviceable structure.

The valve plugs 70 for each of the valve assemblies 24, 34, 38 and 42 are identical in construction and only one will be described in detail. Thus, the valve assembly 24 is shown in detail in FIGURES 2 through 4 and includes a first section which is flanged at opposite ends to be connected to the pipes forming the respective conduits of the concrete pump shown in FIGURE 1. A

section or conduit 100 defines a valve seat 102 for the valve plug 70.

An opening is defined in the upper end of the section 100 which communicates with one end of a sleeve 104 defining the valve chamber for the reciprocating valve plug 70. The sleeve 104 has a slotted clean-out adapter 106 at the upper end thereof with the sleeve 104 and adapter 106 held in assembled relation by bolts 108 having one end secured to the section 100 and the opposite ends extending through a flange 110 formed on the lower end of the cylinder 62. The entire plug valve assembly 24 is held in assembled position by nuts 112 threadedly received on the ends of the bolts 108.

According to one aspect of the invention, the valve plug 70 includes a guide portion which is slightly smaller in diameter than the inner diameter of the sleeve 104 forming the valve chamber. The guide portion 120 has an opening 122 at the upper end thereof which threadedly receives the free end of the piston rod 68 so that reciprocation of the piston rod within the cylinder 62 will reciprocate the guide portion within the valve chamber 104.

The guide portion has a circumferential opening 124 for receiving a bearing 126 which has an outer surface in contacting engagement with the inner surface of the sleeve or valve chamber 104. Of course, any number of 4 bearings may be provided at spaced points on the guide portion and two have been shown for purposes of illustration.

The lower end of the guide portion has a reduced diameter portion for receiving sealing means to effectively seal the space between the guide portion and the inner surface of the sleeve 104. The sealing means 130 includes a plurality of juxtaposed rings 134 surrounding the reduced diameter portion with each of the rings or packing members 134 being V-shaped in cross sectional configuration. The sealing means further includes male and female adapters and 142 disposed above and below the V-shaped packing members 134.

A piston is removably secured to the lower end of the guide portion 120 by bolts 152 extending through openings defined in the guide portion with the bolts being threadely received in openings 154 in the piston 150. The lower end of the piston 150 has a reduced portion 156 which is offset from the axis defining the center of the valve plug. The lower end or distal end of the reduced portion has an arcuate surface 158 which corresponds in contour with the configuration of the valve seat. The reduced portion 156 further includes an angularly disposed surface 160 which merges with a second surface 162 that is disposed perpendicular to the axis of the valve plug and is spaced above the lower end of the reduced portion.

The first surface 160 is in constant communication with the flow of material through the conduit or passage to which the valve is attached. Thus, the surface 160 defines a pressure surface which will at all times orient the plug so that the seating surface 158 is properly aligned with the valve seat. Furthermore, the surface 160 will aid in the opening of the valve since any pressure applied on this surface caused by fluid flowing in the direction indicated by the arrow will result in a vertical component of force due to the angle of the pressure surface relative to the flow of fluid in the passage.

The second surface 162 cooperates with a portion of the peripheral surface of the piston to define a 90 edge, 164, along approximately one-half the circumferential surface of the piston. The edge 164 defines a wiping edge or shoulder which will clean any foreign material or small particles from the inner surface of the valve sleeve or chamber 104 to substantially eliminate any abrasion which may result from small particles being forced between the piston surface and the valve chamber surface. Thus, this wiping action of the piston will substantially increase the service life of the entire valve assembly. Of course the wiping edge will be reciprocated in the leading half of the valve assembly which would be the area most likely to receive abrasive materials in the valve chamber.

A slightly modified form of valve plug is shown in FIGURE 6. Since all of the elements of the valve plug are identical to the valve plug 70 shown in FIGURE 4, like reference numerals for the corresponding parts have been used to identify like parts. The valve plug 170 further includes a fin or divider 172. The fin 172 is preferably formed integral with the surfaces 160 and 162 and the configuration and location of the divider 172 will substantially eliminate any accumulation of concrete material on either of the surfaces 160 or 162. Also, the configuration and more specifically the angle of the free end of the fin will aid in forcing large pieces of aggregate away from the seating surface 158.

The operation of both valve assemblies is readily apparent from the above description. The valve plugs 70 or 170, as well as the piston rod 68 secured thereto, are free to rotate relative to the valve chamber or sleeve 104. During the closing of the valve, the pressure surface 160 will be subjected to the pressure of the material flowing through the conduit or passage in the direction generally designated by the arrow A in FIGURE 3. Thus, the pressure on the surface 160 will at all times properly orient the valve to align the surface 158 with the valve seat 102.

Likewise, the pressure resulting from the flow of material in the conduit or passage will provide a vertical component of force along the axis of the valve plug to thereby aid in opening the valve when the fluid pressure on the head end of the hydraulic cylinder 62 is removed.

The wiping shoulder 164 defined by the surface 162 and the peripheral surface of the piston will provide a true wiping edge for the inner surface of the valve chamher or sleeve 104. This of course is of extreme importance in providing a valve which will have a substantially increased service life. Likewise, making the various parts of the valve plugs separable will considerably decrease the cost of servicing the entire valve plug assembly since any part which may be subjected to the greatest wear during use can readily be replaced without the required replacement of the entire valve assembly.

We claim:

1. In a valve for controlling the flow of aggregate containing material in a passage and having a valve seat therein, and a valve chamber communicating with said passage and valve seat with a valve plug reciprocated in said chamber, the improvement of said plug comprising a cylindrical portion having an axis centrally thereof and a planar portion adjacent one end thereof substantially perpendicular to said axis, means defining a substantially fiat surface extending below said planar portion and inclined with respect to said planar portion, and surface means connecting said flat surface and the peripheral surface of said plug to define a seating segment corresponding to the configuration of said valve seat.

2. A valve as defined in claim 1, including the further improvement of a divider fin extending from said flat surface.

3. A valve as defined in claim 1, in which said surface means extends perpendicular to the axis of said plug.

4. A valve as defined in claim .1, in which said fiat surface merges with said planar portion along a line substantially perpendicular and juxtaposed with the axis of said plug.

References Cited UNITED STATES PATENTS 199,814 1/1878 Fifield 251-118 851,370 4/1907 Nolan 251-324 X 2,188,957 2/1940 Pfauser 277-124 X 2,401,112 5/1946 Saunders 251-324 X 2,420,849 5/ 1947 Wilson 251-326 3,198,123 8/1965 Wilkinson et a1. 103-49 3,207,471 9/ 1965 Williams 251-328 ARNOLD ROSENTHAL, Primary Examiner.

US. Cl. X.R. 251-326; 277-124 

